Of all the tonebenders, I really do like the MkII version - It nails the Hendrix Voodoo Child sound when you put a well tuned wah pedal in front of it too.
I don't think Hendrix ever used a Fuzz Face - If he did, I don't think he liked it from what I have heard from folks supposedly in the know - forget the other benders - build a MkII - you won't be sorry you did.
bajaman

bajaman wrote:I don't think Hendrix ever used a Fuzz Face - If he did, I don't think he liked it from what I have heard from folks supposedly in the know - forget the other benders - build a MkII - you won't be sorry you did.bajaman

I agree. I've only seen one photo with JH having a FF in front of his wah (photo was from his early days). Every other photo has him with it after the wah. What changed? Was the circuit modified to work with a wah? I would guess the whole thing was gutted and a different circuit put in there. It could be anything in there. I'll take another guess and the FF enclosure was used because it's incredibly road worthy. Maybe he could see the future, wanted to throw off greedy pedal manufacturers and destroy the tone of many a Hendrix impersonator?

frank.clarke wrote:Thanks Vanessa, mine goes from pleasant overdrive to Foxx Tone Machine depending on the transistors. It sounds exactly unlike something Mick Ronson would have used. I'll give the AC128s that just arrived a shot and that's it, so under the knife it goes.

I would not waste those on this one. You have to step back... This one is not a top shelf project by any means. Buy up some 2n404's cheap, the crappier the better.

I have heaps of 2n404As with gold legs, but incredible gain for most of them (> 130) Maybe I should try them. Also found a a lot of different version ready for transfer at GGG Tone Bender Mk II Pro.

Should we split off discussion on Mk I vs Mk II? Let me know...

"The whole point of diy is diy. It's not dsoiyathodtr - do some of it yourself and then have others do the rest" (paulc)

I built the Tonebender Mk II, in fact I etched 3 GGG boards and started off with a PNP negative ground configuration, my finding largely:

I had to use a 100k trim pot on Q3 collector to be able to dial in the correct bias. 8k2 did nothingThe very few with <100 hfe from my 2N404A stack didn't work well in Q1, I used an unbranded East German transistor for that position. Experimented with 2N404as in Q2 and Q3 (hfe's 90 and 125 or so) and got very fat fuzz, but a thorough lack of sustainThe sustain problem improved by putting two East German transistors and what I think is a AC151 for Q3 (hfe 125), Q1 is 70; Q2 is 85 or soAfter biasing the circuit up each time I also check the Vc on Q1, and telling by my ears it likes to sit at 4-5VThe circuit is a real good saturated fuzztone that sings in a fuzzy way, it only needs more sustain and maybe more volume. Trying out both Strat and LP it like the LP more than the Strat, and sounds much better with neck pickups than with bridge pu's. It at least wants to see two parallel single coils. All this makes me think the sustain is still a serious problem. Never had that problem with a fuzz face. By itself it's a singular and useable crazy fuzztone that's worth boxing up. Might do so and try a NPN Ge or Si version. After going through some 100 transistors you yearn for silicon, especially since I came across some low gain ones.

NPN GE: went looking through my stash and found some 2SK352,, AC175s and other GEs, but irrespective of the transistor choice I got great fuzz with incredible sustain, but a lot of noise . Didn't take the time to modify the pcb with RF caps or resistors. The transistors are probably too leaky

NPN SI: in this setup as well as in my other configs, I used a 100K pot for the bias so I could always dial in the 'correct gain'. I tried 2N2222, 2N4401, MPSA13, 2N3904 and 2N5088/9. Finally settled for Q1 = 2N2222; Q2 = 2n4401; Q3 = 2N5088. Very low gain silicons didn't work - say hfe < 100

After biasing at 4.5V, it seemed that nothing was lost tone wise raising the bias to 7V - but you win in SNR, treble content and some definition in the sound. This requires only 1k on the collector of Q3 in my setup. When you hit your guitar hard, the bias momentarily drops to 5.8V or something.

Was only trying out the GE's out of curiosity, and because it has a history of being a problematic build.

I was also wondering, is that original Silicon Tonebender by Gus still available?

"The whole point of diy is diy. It's not dsoiyathodtr - do some of it yourself and then have others do the rest" (paulc)

NPN SI: in this setup as well as in my other configs, I used a 100K pot for the bias so I could always dial in the 'correct gain'. I tried 2N2222, 2N4401, MPSA13, 2N3904 and 2N5088/9. Finally settled for Q1 = 2N2222; Q2 = 2n4401; Q3 = 2N5088. Very low gain silicons didn't work - say hfe < 100

are you using the schem from fuzz central with these transistors? i want to mess around with the tonebender circuit but i think silicon transistors would be more my style and much less of a headache to purchase. the fuzz central npn silicon schematic looks like a good starting point.

After biasing at 4.5V, it seemed that nothing was lost tone wise raising the bias to 7V - but you win in SNR, treble content and some definition in the sound.

this is slightly o/t but i've found that a collector reading of ~7v in q2 and q3 of my modified big muff circuit yields the best sound. possibly a secret voltage sweet spot?

NPN SI: in this setup as well as in my other configs, I used a 100K pot for the bias so I could always dial in the 'correct gain'. I tried 2N2222, 2N4401, MPSA13, 2N3904 and 2N5088/9. Finally settled for Q1 = 2N2222; Q2 = 2n4401; Q3 = 2N5088. Very low gain silicons didn't work - say hfe < 100

are you using the schem from fuzz central with these transistors? i want to mess around with the tonebender circuit but i think silicon transistors would be more my style and much less of a headache to purchase. the fuzz central npn silicon schematic looks like a good starting point.

I had etched some GGG boards, so I used those, but the schematic is largely the same.

After biasing at 4.5V, it seemed that nothing was lost tone wise raising the bias to 7V - but you win in SNR, treble content and some definition in the sound.

this is slightly o/t but i've found that a collector reading of ~7v in q2 and q3 of my modified big muff circuit yields the best sound. possibly a secret voltage sweet spot?

This I find very interesting, but there must be some mathematic reason for this. Anyway I would start out making SI TB before doing GE versions to avoid frustrations, I learned the hard way. Had a fair selection of transistors that had done well in other builds, but they didn't sing in my Ge Tonebender builds.

JimiB wrote:I am trying to create a really accurate MKII and I was looking at the D.A.M. stuff and he is using a trimpot but also the 8.2K resistor. Do you think the trim pot is a 100K in series with that 10K and subbing for the Q2 collector r?